With the development of science and technology, sensors are applied widely, and it is imperative to manufacture sensors which are portable and inexpensive and can be manufactured at a large scale. Flexible substrate-based gas sensors essentially improve a lot of problems due to many advantages such as flexibility thereof or the like. Thereby, the flexible substrate-based gas sensors have a broader application prospect.
NO2 belongs to typical atmospheric pollutants, and primarily comes from burning of fossil fuel and automobile exhaust pollution. NO2 is one of industrial pollutants which cause problems such as acid rain, photochemical smog or the like, and causes respiratory disease as it easily reacts with hydrocarbon in the sunshine, which seriously threatens the health and survival of human beings. With the rapid development of industries, people pay more and more attention to monitoring of NO2. Researches on NO2 gas sensors are a hotspot at home and abroad all the time. In order to improve the sensitivity characteristics of the sensors, people have put much effort on selection and modification of material. With the rapid development of Internet of Things, sensors with a portable design and low power consumption are widely concerned. Therefore, it is a very important task to manufacture a flexible NO2 gas sensor for detection at room temperature.
A conventional method for manufacturing a flexible NO2 gas sensor for room temperature is to directly deposit a sensitive film on a surface of a flexible substrate. In the process of manufacturing a sensor, hygroscopic treatment is firstly performed on the substrate, and then sensitive material is deposited on a surface of the substrate using dip-coating, dispensing or self-growing method. The sensitive film manufactured in this way has a non-uniform thickness, and poor adhesion with the substrate.